Method for removing back-filled pore-filling agent from a cured porous dielectric

Abstract

A method for preparing a porous dielectric is described. In particular, the method includes removing pore-filling agent from pores in a cured porous dielectric layer, wherein the pore-filling agent was back-filled within the pores following the removal of a pore-forming agent during a curing process. The removal of the pore-filling agent includes heating a substrate holder upon which the substrate rests to a holder temperature greater than 100 degrees C. and less than 400 degrees C., and while heating the substrate holder, exposing the substrate to electromagnetic (EM) radiation, wherein the EM radiation includes emission at a wavelengths within the ultraviolet (UV) spectrum, visible spectrum, infrared (IR) spectrum, or microwave spectrum, or combination thereof.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]Pursuant to 37 C.F.R. § 1.78(a)(4), this application claims the benefit of and priority to U.S. Provisional Application No. 61 / 950,949 filed on Mar. 11, 2014, which is expressly incorporated by reference herein in its entirety.FIELD OF INVENTION[0002]The invention relates to a method for preparing a low dielectric constant (low-k) dielectric film, patterning the low-k dielectric film, and integrating the low-k dielectric film with subsequently formed metal interconnects.BACKGROUND OF THE INVENTIONDescription of Related Art[0003]As is known to those in the semiconductor art, interconnect delay is a major limiting factor in the drive to improve the speed and performance of integrated circuits (IC). One way to minimize interconnect delay is to reduce interconnect capacitance by using low dielectric constant (low-k) materials as the insulating dielectric for metal wires in the IC devices. Thus, in recent years, porous dielectrics have been de...

AI Technical Summary

Benefits of technology

This approach effectively prevents plasma-induced damage and ensures the clean removal of the pore-filling agent, maintaining the low dielectric constant of the porous dielectric film, thereby enhancing the mechanical strength and integration of the material with metal interconnects.

Problems solved by technology

As is known to those in the semiconductor art, interconnect delay is a major limiting factor in the drive to improve the speed and performance of integrated circuits (IC).

Porous dielectrics are less robust than more traditional silicon dioxide, and the mechanical strength deteriorates further with the degree of porosity.

The porous dielectrics can easily be damaged during subsequent mechanical and chemical processing, thereby making desirable a mechanical strengthening or curing process.

Once cured, porous dielectrics face yet additional challenges.

When porous dielectric films are patterned for subsequent metallization, the dielectric can be easily damaged during exposure to plasma chemistry, such as the plasma chemistries used in etch and ash, causing the effective k value to increase after integration.

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